Mike hit all the points right on, if you aren't prone to motion sickness when you fly or ride in a car then you should not have any problems on a ship, ships have wonderful stabalizers and most of the time you hardly feel the movement except at night when the captain "floors it" lol to get to the next port of call. The patch is for people who suffer from motion sickness, The OTC formulas work really well, i have had great results with the ginger remedy, if i am feeling the least bit queasy i will munch on a ginger candy or have a glass of REAL gingerale.